Generating plant breakdowns during heat wave strain power grid.

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Texans are being asked to conserve power during the hottest part of the day, from 3 p.m. to 7 p.m., in an effort to avoid rolling power outages as temperatures climb this week:

• Turn off all unnecessary lights, appliances and electronic equipment.

• When at home, close blinds and drapes that get direct sun, set thermostats to 80 degrees or higher, and use fans to cool the air. Note: In extreme heat, if there is more than a 20-degree difference between the outside temperature and the thermostat setting, the AC compressor does not cycle off long enough to give it sufficient rest and works at a level that could lead to damage.

• When away from home, set the thermostat to 85 degrees and turn off all fans before you leave. Block the sun by closing blinds or drapes on windows that will get direct sun.

• Do not use your dishwasher, laundry equipment, hair dryers, coffee makers or other home appliances during the peak hours of 3 p.m. to 7 p.m.

• Avoid opening refrigerators or freezers more than necessary.

• Use a microwave for cooking instead of an electric range or oven.

• Set the pool pump to run in the early morning or evening instead of the afternoon.

• Businesses should minimize the use of electric lighting and electricity-consuming equipment as much as possible.

• Large consumers of electricity should consider reducing nonessential production processes.

Source: CPS Energy, Electric Reliability Council of Texas

The heat wave this week, which is forecast to peak at 106 degrees Sunday, is bringing a fresh round of pleas from the state electrical grid operator to conserve energy.

“Until we get a break in the temperature, there are going to be more days like this, and it’s really important we get word out to consumers to help out, particularly during the peak hours between 3 p.m. and 7 p.m.,” said Dottie Roark, spokeswoman for the Electric Reliability Council of Texas, which manages the grid.

“At the risk of sounding like a broken record, if you can turn your thermostat up a couple degrees,” that would really help, she said, noting that air conditioners are the biggest residential drain on electricity.

An increasing number of power plants across the state are breaking down or are unable to run at full capacity, exacerbating electricity shortages as extreme temperatures continue to drive record demand. Coastal wind that had been adding capacity also dropped Wednesday, Roark said.

“We really missed having that extra coastal wind that’s been helping us out,” she said.

ERCOT called an emergency alert to Level 2A a little after 3 p.m. Wednesday, and Roark warned such alerts likely would continue through the weekend.

Level 2A means reserve grid capacity has fallen below 1,750 megawatts, and ERCOT may call on industrial customers who have agreed previously to shut down equipment in an emergency. On Wednesday, it only needed to use about half of that capacity, Roark said.

ERCOT was down about 5,000 megawatts Wednesday, with two large power plants failing unexpectedly, while others have been unable to run full-bore after being overtaxed for weeks on end. One megawatt powers about 200 homes.

CPS Energy didn’t have any unplanned power plant outages Wednesday, a spokeswoman said.

Good thing, since the utility hit an all-time high for electrical use of 4,800 megawatts at 5 p.m.

CPS deployed its Peak Saver program, where it cycles off residential air conditioner compressors for 10 to 15 minutes every hour during peak times, but it didn’t tap its demand response program, which asks participating companies and institutions to reduce load by at least 100 kilowatts each.

That’s because the deal it cuts with those customers only allows CPS to request the reduction for either 20 or 25 days during the summer — and the utility has already used it 18 times.

“We’re trying to be very judicious,” said Lisa Lewis, director of corporate communications. “Especially since the weather is supposed to be heinous for the rest of the week.”

State officials remain hopeful they can stave off rolling power outages like the state saw Feb. 2, when dozens of power plants failed due to extreme cold temperatures.

That was only the third time in 21 years that ERCOT had to institute rolling blackouts, Roark said.